1. Field of the Invention
The present invention relates to a cover for a cutting blade used for a reaper in which a cutting blade reciprocates.
2. Description of the Related Art
Conventionally, as shown in FIG. 9, a hand-held brush cutter 100 provided with an engine 101 mounted at one end thereof and a disk-shaped cutter 102 at the other end thereof that is rotated to cut bushes and the like has been used.
Recently, as shown in FIGS. 7 and 8, there has been proposed a hand-held reaper 12 comprising an engine 13 at a rear end thereof and a cutting blade 11 at a forward end thereof that reciprocates, as a power driven reaper for cutting off nuts or branches that cannot be handled by the brush cutter 100. The cutting blade 11 is constituted by a bar-shaped shank member 16 attached to a driving unit. 15 of the reaper 12 and a plate-shaped blade member 17 integral with the shank member 16 and having a cutting portion 18 at a tip end thereof that is orthogonal to the shank member 16.
While a variety of cutter covers are used for protecting disc-shaped cutters in the brush cutter (see FIG. 1 of Japanese Laid-Open Patent Publication No. Sho 63-56213), there is a need for a protection cover suitable for a cutting blade for a power driven reaper that has a shank member at a base end thereof and a cutting portion at a tip end thereof.
In consideration of above-mentioned circumstances, it is an object of the invention to provide a cutting blade cover for a cutting blade of a reciprocating type that is easily attachable and detachable, is highly retentive, and is fabricated at a low cost.
In one aspect of the invention, a cutting blade cover for protecting a cutting blade constituted by a shank member connected to a driving unit of a reaper and a plate-shaped blade member formed continuously with the shank member and having a cutting portion at a tip portion thereof that is orthogonal to the shank member, comprises: a bag-shaped accommodating portion for accommodating the cutting portion provided at the tip portion of the plate-shaped blade member; and a shank retaining portion for retaining the shank member.
According to the cutting blade cover described above, the cutting portion at the tip end is covered and protected and the tip portion is retained by the bag-shaped accommodating portion, and the rearward shank member is retained by the shank retaining portion integral with the bag-shaped accommodating portion. Therefore, the cover is easily attachable and detachable and is highly retentive.
In another aspect of the invention, the cutting blade cover further comprises an elastic portion that is formed continuously with a tip portion of the bag-shaped accommodating portion and is elastically deformed when an external force is applied to the bag-shaped accommodating portion.
According to the cutting blade cover described above, since the elastic portion is provided at the tip end of the bag-shaped accommodating portion for accommodating the cutting portion, the external force applied to the tip portion of the cutting blade is relieved due to the elastic portion. Therefore, protective effect for the tip portion of the cutting blade is further enhanced, and the cutting blade cover itself is protected. Furthermore, because only the extension of the tip of the bag-shaped accommodating portion provides the elastic portion without a substantial increase in weight and cost, this cutting blade cover is suitable as a protection cover of this type.
In still another aspect of the invention, the cutting blade cover further comprises a first displacement restricting portion provided between the bag-shaped accommodating portion and the shank retaining portion, for supporting a base end portion of the plate-shaped blade member and the shank member so as to restrict displacement of the cutting blade from the bag-shaped accommodating portion.
According to the cutting blade cover described above, the first displacement restricting portion serves to restrict axial movement of the cutting blade.
In a further aspect of the invention, the cutting blade cover further comprises a base plate portion covering a side surface of the plate-shaped blade member, the bag-shaped accommodating portion and the shank retaining portion being provided on the base plate portion; and a second displacement restricting portion provided along a rear peripheral portion of the base plate portion, for supporting a base end portion of the plate-shaped blade member of the cutting blade so as to restrict displacement of the cutting blade from the bag-shaped accommodating portion.
According to the cutting blade cover described above, movement of the cutting blade as large as the base plate portion is restricted by the second displacement restricting portion.
It is preferable that the bag-shaped accommodating portion and the shank retaining portion are formed of synthetic resin integrally with the base plate portion covering the side surface of the plate-shaped blade member.
According to the cutting blade cover having such a structure, the cutting blade cover can be fabricated easily and at a lower cost.
It is preferable that the bag-shaped accommodating portion includes a ridge-shaped retaining portion extending in a direction of the shank to sandwich and securely retain a tip portion of the cutting blade with the cutting portion of the cutting blade accommodated in the bag-shaped accommodating portion.
According to the cutting blade cover having such a structure, the retaining portion serves to sandwich and securely retain the tip portion and the play of the tip portion is thereby avoided. In addition, since the retaining portion is ridge-shaped and partially formed in the bag-shaped accommodating portion in the direction of the shank, it is easy to make a spacing of the retaining portion smaller to be adapted to the plate-shaped blade member having a relatively small thickness.
These objects as well as other objects, features and advantages of the invention will become more apparent to those skilled in the art from the following description with reference to the accompanying drawings.